This invention relates to the construction of a tubular frame for a permanent magnet direct current motor. The tubular frame is constructed of a plurality of frame modules of equal axial length and cross-sectional dimensions. The modules are connected together end-to-end to form the tubular frame to accommodate a suitably sized rotatably mounted armature. The general disclosure of this invention relates equally to motors and generators. For purposes of illustration the specific disclosure of this application is directed to permanent magnet, direct current motors.
Direct current motors are manufactured in a wide variety of diameters and lengths. Many different sizes are necessary because of space requirements which dictate overall motor dimensions, and power requirements, which are generally proportional to armature length and diameter.
Heretofore, this has meant the fabrication of each motor configuration in a wide variety of cross-sectional dimensions as well as a variety of lengths, such as 4", 8", 12", etc. The resulting number of different motor frame components and magnets necessary for the manufacture of all of these various sizes of motors, results in increased manufacturing costs and inventory expense.
According to the invention disclosed and described in this application, manufacturing and inventory expenses can be reduced substantially by forming motor frames of different lengths from a plurality of uniformly sized components for any given motor diameter.